The Prevention of Wave Erosion

1. The Prevention of Wave Erosion Breakwaters, Jetty’s and Dune Vegetation Kyle Rosbrook

2. What is Dune Vegetation? Dune Vegetation is naturally occurring grass, vegetation, weeds, brush, etc. to keep down wind speeds going out to sea. The slowing of the wind keeps more sand on the beach, preventing faster erosion.

3. Dune Vegetation Dune Vegetation Can Dune Vegetation Cannot prevent direct wave erosion – dune sand is not strongly bound by roots under wave attack survive direct wave attack – much of the seaward vegetation will be destroyed in a storm tolerate excessive physical damage caused by people, stock or vehicles tolerate mismanagement such as mowing, which destroys some species and juveniles of others, and topsoiling, which prevents free drainage and is unsuitable for growth of many natural dune species tolerate overfertilising, which can be toxic to some species tolerate introduction of unsuitable plant species – some undesirable plants displace natural vegetation; others, such as palm trees, do not reduce wind erosion and accelerate wave erosion when they fall • prevent wind erosion by decreasing wind speed at ground level • build up sand dunes and thus reduce the extent of recession produced by a storm • reduce wave erosion caused by overwashwhere dense vegetation exists • regenerate naturally after storm damage, where dune management allows • tolerate a hostile environment of high winds, salt spray, sandblast, covering by sand, sandy soil and little water • accept massive movements of the dunes, both vertically and horizontally • function as a self-supporting community where plants are mutually dependent for protection and nutrient supply

4. Breakwaters…. • A breakwater is a man-made mechanism designed to lessen the intensity of wave action and ultimately reduce the destruction of the coast • It can be floating of solid(often concrete) and can be out hundreds of feet in shallow water of attached to the coast at one end • When the waves hit them, there destructive power is reduced, and the water coming to shore is far less powerful and less harmful to coastlines

5. Breakwater… • Breakwaters can vary is size, depending on the size needed to stop or slow the waves. • The are often designed with spaces water can pass through, or over top, both allowing water to pass with less force This Breakwater in Vietnam cost 1.2 Billion dollars to construct.

6. Floating breakwater • http://www.eco-marine.com/video/swb.html • This floating breakwater serve the same purpose, to slow the destructive power but allowing the water that pass in a natural way.

7. Jetty’s • Similar to a breakwater, a jetty’s purpose it to stop the spread/ destruction of the coast. • They are located at river or lagoon mouths where it meets the ocean, so that the water cannot flow further down the coastline or into the river causing further erosion

8. Jetty…..Art Although not functional, this spiral jetty was created by Robert Smithson in 1970. It is 15 feet wide and 1500 feet long.